Improvement in steam-boiler furnaces



J. HOWES.

Improvement in Steam-Boiler Furnaces. No. 132,466. Patented Oct.22,1872.

Wfiqessas TI E 11h: r

STATES PATENT OFFICE.

JOHN HOWES, OF WORCESTER, MASSACHUSETTS.

IMPROVEMENT IN STEAM-BQILER FURNACES.

Specification forming part of Letters Patent N0. 132,466, dated October22, 1872.

To all whom it may concern:

Be it known that I, JOHN HOWES, of the city and county of Worcester andCommonwealth of Massachusetts, have invented certain new and usefulImprovements in Steam- Boiler Safety-Regulator and Heat-Economizer and Ido hereby declare that the following is a full, clear, and exactdescription of the same, reference being had to the accompanying drawingwhich forms a part of this specification, in which- Figure 1 representsa transverse vertical section through the front end of the boiler andfurnace; and Fig. 2 represents a longitudinal vertical section throughthe center of boiler, furnace, and smoke-fines.

The nature of my invention consists in the combination, with asteam-boiler and its furnace, of a safety-regulator or under-draft fluefor regulating the heat upon the surface of the boiler, as hereinafterdescribed.

In the drawing, the part marked A repre sents the boiler, which, in thepresent instance, is an ordinary horizontal, cylindrical, tubularboiler; but my improvements may be used with boilers of any other class.B B indicate the brick walls of the furnace, and upon which the boiler Ais supported. 0 indicates the furnace, and D the ash-pit. E indicatesthe bridge-wall; F, the chimney-flue; and G, the grate and fire. Thefurnace is made sub stantially of the usual form, and from the ashpit D,or from the space below the grate G, I construct a flue or passage, H,direct to the chimney-flue F. This flue H is fitted with a damper, I, bymeans of which the passage can be opened and closed at pleasure by theperson attending the fire. The usual course of the smoke and gases fromthe fire is along the under side of the boiler, the passage J, throughthe tubes K to the front end of the boiler, back over the top surface ofthe boiler in the passages L, and from thence through the funnel M tothe chimney-flue F. The products of combustion follow this course whenthe damper I in the flue H is closed, the flame from the fire rising andimpinging upon the plates of the boiler, as indicated in Fig. 1; butwhen the damper I is opened and the damper in the smoke-flue M closed,the draft to the chimney-flue F is then sent direct through the flue H,and the products of combustion are drawn downward through the grate, theflame being carried away from the boiler A and down into the ash-pit D,as indicated in Fig. 2. It will not in all cases be necessary to closethe damper R to produce the desired effect, unless the upper flues arequite direct, or the under flue H is of considerable length, and in manycases it may be desirable to leave the damper R open to permit a currentof air to carry away the heat radiated from the V walls.

When the fire is running in the ordinary manner, the door N of theash-pit is left open for the entrance of air but when the damper I, influe H, is opened, the door N is to be closed, and the furnace-door O isopened to let the air in upon the top of the fire; or, a sideair-passage, P, may be provided instead of using the door. This sidepassage would not be required, however, unless the mechanism wasarranged to operate automatically, as hereafter described. The damper Imay be arranged either as a sliding or rotating damper, and it may beoperated by means of a hand-bar, g, or be weighted and connected to somesuitable automatic indicator worked by the variation of the water-levelor steam-pressure in the boiler, as preferred. In the latter case thecover P of the air-passage P should be arranged to operate in concerttherewith, as may also the damper R in the smoke-funnel M.

Among the advantages gained by the use of the under flue H and damper Imay be mentioned the following: It enables the attendant to instantlydivert the heat away from the boiler, in case the water should becometoo low from derangement of the pumps or from other cause, or in case ofan excess of D steam, thus guarding against an explosion, or preventingany straining of the boiler-plates and rivets. It thus establishes afeeling of safety in the minds of the attendant and others in thevicinity. In case the fire becomes dead at the under side, by changingthe direction of the draft to the flue H for a short time, the deadcoals become rekindled. It prevents dust or gas from escaping into theroom while removing ashes or stoking the fire.

In case of banked fires, the draft from above and below can be soregulated, by properly The combination, with a steam-boiler andadjusting the damper I, as to preserve the its furnace, of an under flueor safety-draft fire with but slight heat upon the boiler and passage H,substantially as and for the pur' when blowing off, by opening thedamper I, poses set forth.

all liability of burning the boiler is obviated. JOHN HOWES.

Having described my improved steam-boil er, safety-regulator, and heateoonomizer, Witnesses:

what I claim therein as new and of my in- THOsELDODGE,

vention, and desire to secure by Letters Pat- E. E. MOORE.

ent, is--

